The present invention relates to drive systems for motor vehicles. In particular, the present invention relates to belt drive systems that eliminate or substantially reduce the flexing of jackshafts and driveshafts occurring in drive systems.
Chain and belt drive systems for motor vehicles such as snowmobiles are essential components for transferring power from an engine to the points of application, such as snowmobile tracks. Power from an engine is first transferred to a jackshaft, causing the jackshaft to rotate. The jackshaft is attached to a drive system that transfers the rotational energy to a driveshaft. The driveshaft then transfers that power to the track to propel the snowmobile. A common problem with the previous chain and belt drive systems, however, is flexing of the jackshaft and driveshaft. The chains or belts are tightly looped around pulleys of the drive system, which are correspondingly attached to the jackshaft and driveshaft. Such tight looping causes tension between the pulleys, causing the jackshaft and driveshaft to flex under the stress. This results in damage to the jackshaft and driveshaft, and misalignment of the chain or belt—all of which reduce performance of the drive system.
In addition, chain drive systems experience additional complications associated from the use of a chain. First, chains require lubrication, such as oil, to ensure adequate performance. Lubricating fluids generate hydroscopic drag, reducing performance of the drive system. Chain drive systems also suffer from impediments attributed to chain-to-sprocket connections. The metal-to-metal interaction of a chain to a sprocket causes friction, which also reduces performance of the drive system. Finally, chains also can be extremely destructive upon cracking and shattering. If a chain shatters, it can seriously damage the chain case and the engine, both of which can be very expensive to repair.